I've been having Sonera (or TeliaSonera) Internet connection for ages. Occasionally I refer to my own IP with the DNS-name and now they chose to change them. It looks like they chose to change the subscriber identifier part of FQDN to indicate IPv4 address instead of some sort of internal identifier.
Typical Sonera broadband dynamic IP-address' reverse-DNS FQDN has format:
- Connection type: (fixed: dsl or cable)
- City identifier: always 3 characters
- Gateway identifier: (example: brasgw1)
- Subscriber identifier: hex-decimal -combo
- Dynamic broadband pool identifier: (fixed: dhcp.inet.fi)
A regexp would be:
^(dsl|cable)-([a-z]{3})([a-z0-9]+)-([0-9a-f]{6,}-\d{1,3})\.dhcp\.inet\.fi$
The old subscriber identifier had 8 hex digits, a dash and 1-3 decimal digits. For example: fe82eb00-56
The new subscriber identifier has 6 hex digits to represent the first 3 bytes of IPv4 address, a dash and 1-3 decimal digits for the last byte of IPv4 address. For example IPv4 address of 21.32.43.54 would be: 15202b-54
Wishful thinking: Are they finally preparing to offer IPv6?